/**
 * Copyright (c) 2021 OceanBase
 * OceanBase CE is licensed under Mulan PubL v2.
 * You can use this software according to the terms and conditions of the Mulan PubL v2.
 * You may obtain a copy of Mulan PubL v2 at:
 *          http://license.coscl.org.cn/MulanPubL-2.0
 * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
 * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
 * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
 * See the Mulan PubL v2 for more details.
 */

#ifndef _OB_RAW_EXPR_ADD_TO_CONTEXT_H
#define _OB_RAW_EXPR_ADD_TO_CONTEXT_H
#include "sql/optimizer/ob_logical_operator.h"
#include "sql/resolver/expr/ob_raw_expr.h"

namespace oceanbase {
namespace sql {
/**
 *  This class is used to traverse an expression tree in a post-order fashion to
 *  add all required expressions into the context data structure, which is used
 *  during output expr allocation.
 */
class ObRawExprAddToContext : public ObRawExprVisitor {
  public:
  ObRawExprAddToContext(common::ObIArray<ExprProducer>* ctx, uint64_t id)
      : ctx_(ctx), consumer_id_(id), keep_working_(true)
  {}
  virtual ~ObRawExprAddToContext()
  {}

  /**
   *  The starting point
   */
  int add_to_context(ObRawExpr& expr);

  /// interface of ObRawExprVisitor
  virtual int visit(ObConstRawExpr& expr);
  virtual int visit(ObVarRawExpr& expr);
  virtual int visit(ObQueryRefRawExpr& expr);
  virtual int visit(ObColumnRefRawExpr& expr);
  virtual int visit(ObOpRawExpr& expr);
  virtual int visit(ObCaseOpRawExpr& expr);
  virtual int visit(ObAggFunRawExpr& expr);
  virtual int visit(ObSysFunRawExpr& expr);
  virtual int visit(ObSetOpRawExpr& expr);
  virtual int visit(ObWinFunRawExpr& expr);
  virtual int visit(ObPseudoColumnRawExpr& expr);

  private:
  int add_expr(ObRawExpr& expr);
  // types and constants

  private:
  // function members
  private:
  common::ObIArray<ExprProducer>* ctx_;
  uint64_t consumer_id_;
  bool keep_working_;
  // disallow copy
  DISALLOW_COPY_AND_ASSIGN(ObRawExprAddToContext);
};
}  // namespace sql
}  // namespace oceanbase

#endif  // _OB_RAW_EXPR_ADD_TO_CONTEXT_H
